Tow Tug-of-War

Brakes, suspension and handling add up when hauling heavier loads

By H. Kent Sundling

The mentality of bigger is bigger is evident in the truck market as each new model boasts higher payload and towing capacity. One-ton dually models now have a payload of 5,000 lb. and are rated to tow more than 20,000 lb. Can braking, suspension and handling keep up when towing a heavy load?

A 5" to 6" squat changes the pinion angle, causing the driveshaft, including U-joints, to level out and vibrate. Braking issues with the truck and trailer can result as well.

The common, though short-term, fix for a squatting truck is to add shim blocks between the rear axle and leaf springs. Long-term fixes include a complete suspension replacement and add-on airbag kits. The most effective air suspension systems automatically level out the pressure inside airbags with an onboard air compressor.

Aftermarket options. Auto Flex air ride installs without welding or drilling by replacing the factory leaf springs, eye to eye. A tracking bar anchors the suspension side-to-side and has hydraulic shock absorbers. A dump valve lowers the truck to ease hitching to a trailer. Onboard air via a compressor and tank bolted to the truck frame (as opposed to taking up bed space) is also a plus.

Auto Flex’s single-stage airbags self-center and roll to give on corners. No drilling or welding is required to install. The on-board air compressor adjusts automatically to match the load. Kelderman also makes replacement suspension systems.

For additional airbags, Air Lift’s LoadLifter 5000 kit has a remote manifold that is connected to the compressor under the bed, which is operated by remote control. Firestone’s Ride-Rite also makes airbag kits.

It’s important to remember that adding accessories to a truck’s suspension does not increase factory gross vehicle weight rating (GVWR), axle weight rating or payload. The goal is to enhance what you have for maximum load stability.

Air ride suspension is catching on for hardworking farm pickups—just add an air horn and air seat.

Standards in Limbo

The 2013 model year trucks were supposed to meet new towing standards and practices—but that didn’t happen. With guidance from SAE International and agreement from the manufacturers, standardized testing, known as J2807, would allow consumers to evaluate trucks based on factual and comparable numbers.

Toyota implemented the standard first, in 2011, and actually lowered its tow rating on the Tundra and Tacoma. This summer, General Motors lowered its tow ratings on all 2013 models except the 3500. The next day, Ford announced it wouldn’t change its ratings until it had a significantly redesigned truck, which is slated to occur with the 2014 models. As a result, GM pulled back its new ratings. Chrysler’s Ram has never revealed its J2807 numbers to the public.

Stay tuned for progress to standardize towing testing and reporting.

Visit www.FarmJournal.com/towing for more information on the new towing standards and aftermarket products to improve towing performance.